Pinterest Advertising Will Be Huge With Retailers Because Pinners Spend More On E-Commerce

The knock on social media was that it would never drive a lot of paying customers to retail sites, because people are on social networks to connect with friends, not to shop.

But Pinterest is proving to be an exception to that rule. The company's announcement yesterday that it would begin experimenting with "Promoted Pins" will cause major retailers to rejoice. Here's why:

Pinterest users make the largest purchases among customers referred to e-commerce sites by social media, with an average order value of $93 in this year's second quarter, according to Monetate. (See chart, below.)

While e-mail, search and other sources of customers, or "referrals," are still more effective as referral sources, social media is gaining. Customers referred by social media are making larger and larger purchases, $87 on average in the second quarter, or $11 more than a year before.

Pinterest's move toward ads also comes days after Instagram's CEO suggested that the photo-sharing service might also position itself as a social commerce platform for brands and retailers.